1. Technical Field
This invention relates in general to data access and storage devices, and in particular to disk drives. Still more particularly, the present invention relates to a system and method of activating a pumping system in a disk drive with the actuator.
2. Description of the Related Art
Disk drives, also called disk files, are information storage devices that use a rotatable disk with concentric data tracks containing the information, a head or transducer for reading and/or writing data onto the various tracks, and an actuator connected to a carrier for the head for moving the head to the desired track and maintaining it over the track centerline during read and write operations. The most common form of actuator is a rotary voice coil motor (VCM) actuator that moves the head carrier in a nonlinear, generally arcuate path across the disk. There are typically a number of disks mounted on a hub that is rotated by a disk drive motor, also called a spindle motor, and a number of head carriers connected to the actuator for accessing the surfaces of the disks. A housing supports the drive motor and head actuator, and surrounds the heads and disks to provide a substantially sealed environment. In conventional magnetic recording disk drives, the head carrier is an air-bearing slider that has an air-bearing surface (ABS) designed to enable the slider to xe2x80x9cflyxe2x80x9d or ride on a bearing of air above the disk surface when the disk is rotating at its operating speed. The slider is maintained next to the disk surface by a biasing force from a suspension that connects the slider to the actuator. The suspension is attached to a rigid arm connected to the actuator.
Contact start/stop (CSS) disk drives operate with the slider in contact with the disk surface during start and stop operation when there is insufficient disk rotational speed to maintain the air bearing. To minimize the effect of xe2x80x9cstictionxe2x80x9d, i.e., the static friction and adhesion forces between the very smooth disk surface and the slider, CSS disk drives often use a dedicated xe2x80x9clanding zonexe2x80x9d where the slider is parked when the drive is not operating. The landing zone is typically a specially textured, non-data region of the disk.
In contrast to CSS disk drives, xe2x80x9cload/unloadxe2x80x9d disk drives address the stiction problem by mechanically unloading the slider from the disk when the power is turned off, and then loading the slider back to the disk when the disk has reached a speed sufficient to generate the air bearing. The loading and unloading is typically done by means of a ramp that contacts the suspension when the actuator is moved away from the data region of the disk. The slider is thus parked off the disk surface with the suspension supported in a recess of the ramp. Load/unload disk drives are more commonly used in laptop and notebook computers because the parking of the slider on the ramp away from the disk surface also provides some resistance to external shocks caused by moving or dropping the computer.
To improve the performance of disk drives, particularly the rate at which the recorded data can be accessed, it is desirable to rotate the disk at high rotational velocities. In addition, it is desirable to place the data tracks as close together as possible to maximize the data storage capacity. However, when conventional disk drives, such as commercially available 3.5 inch and 2.5 inch form factor drives, are rotated at high rotational velocities they consume excessive power and generate excessive heat in the disk drive housing. In addition, high speed disk rotation causes airflow-induced disk xe2x80x9cflutterxe2x80x9d and vibration of the suspension and/or arm, which makes it difficult for the read/write head to locate the proper data track. This is referred to as track misregistration (TMR).
The use of a hermetically sealed disk drive housing containing a gas other that air, such as helium, to reduce the effect of heat generation within the housing has been proposed, as described in U.S. Pat. No. 4,367,503 and Japanese published patent application JP8077527A. IBM Technical Disclosure Bulletin, Vol. 23, No. 9 (February 1981), describes a removable disk pack mounted on a drive apparatus that uses reduced air pressure around the rotating disks to reduce the effects of heat generation and air turbulence. Japanese published patent application JP7021752A describes a test apparatus that uses a vacuum pump to remove air from within the test chamber for the purpose of testing the head carrier-disk interface. Japanese published patent application JP 10222960A describes an optical CD-ROM drive with a vacuum pump for removing air to decrease air resistance and eliminate dust particles.
In another prior art example, U.S. Pat. No. 6,144,178, a system for reducing the operational pressure inside a disk drive assembly is disclosed. However, this design requires a dedicated electrical motor, which implies the use of expensive additional parts in the disk drive. Moreover, the motor size or volume is severely constrained, which in turn constrains the amount of energy that can be safely dissipated. Consequently, the pumping rate is relatively slow. Thus, an improved system and method for reducing the operational pressure inside a disk drive assembly at high rotational velocities without consuming excessive power and without generating disk flutter or vibration of the suspension or arm would be desirable.
In one embodiment of the present invention, a disk drive having an actuator-activated pumping mechanism is disclosed. The pumping mechanism creates a low pressure operating environment for the disk drive in order to enhance the performance of the drive. Through the use of an engaging element, the actuator motor acts to drive a pumping element. This design does not use a separate electrical motor to evacuate the disk drive housing. Instead, the natural motion of the actuator provides the necessary power to drive the pumping element.
The foregoing and other objects and advantages of the present invention will be apparent to those skilled in the art, in view of the following detailed description of the preferred embodiment of the present invention, taken in conjunction with the appended claims and the accompanying drawings.